The invention relates to a scraper device, as well as a construction machine.
A scraper device for a milling drum mounted in a construction machine at a machine frame in lateral walls, with a scraper blade arranged in a height-adjustable fashion behind the milling drum when seen in the direction of travel, is known from DE 10 2005 058 102. With this scraper device, the lower part of the scraper blade can glide over the ground surface milled off by the milling drum, with the scraper blade being guided in a height-adjustable fashion relative to the milling drum.
From DE 35 28 038, it is known in a scraper device with a single-part scraper blade to use a scraper blade capable of swivelling. A laterally arranged retaining groove causes the lifting movement of the scraper blade to turn into a swivelling movement towards the end of the path of a lifting cylinder.
It is also known from U.S. Pat. No. 5,505,598 and U.S. Pat. No. 5,474,397 to use the lifting cylinder for the swivelling movement, in which case it is necessary, however, to manually remove bolts for unlocking.
In the single-part scraper devices according to the state of the art mentioned above, access to the drum is achieved by means of a large lifting capacity of the scraper blade without swivelling.
In summary, the known state of the art has the following disadvantages:
Lifting cylinders simultaneously designed for lifting as well as for swivelling have a too large design height,
the swivelling radius is larger with these solutions, which requires the rear travel drive units to be arranged far towards the rear,
manual removal of the bolts is time-consuming and requires effort,
if one of the bolts gets jammed, it needs to be removed manually using a tool, which involves a lot of effort,
the use of bolts has the disadvantage of a small contact surface, which results in a high surface pressure and high wear and tear,
the achievable swivelling angle is too small,
the design height of single-part scraper devices is so large that it is suitable only where the milling drum is arranged at the rear end of the construction machine, and not between the front axle and the rear axle below the machine frame.
It is therefore an object of the invention to create a scraper device, the scraper blade of which is capable of swivelling with a large swivelling angle at a small swivelling radius, which realizes a low design height and does not require manual operation.
The invention provides in an advantageous manner that the upper part of the scraper blade is attached, at the upper end, in an articulated fashion to swivel about a swivelling axis parallel to the axis of the milling drum, that the scraper blade, when in operating position, is engaged with lateral retaining devices in the lateral walls, which retain the scraper blade in a position running essentially orthogonally to the ground surface, that a swivelling device is capable of swivelling the scraper blade about the swivelling axis when the scraper blade is disengaged from the lateral retaining devices, and that the swivelling device, at the upper end of the upper scraper blade, is provided with an operating device articulated between a permanently installed part of the construction machine and the upper part of the scraper blade.
The invention thus provides that the swivelling device is provided with an operating device which is articulated, in a space-saving manner, at the upper end of the upper scraper blade between a permanently installed part of the construction machine and the upper part of the scraper blade. The operating device is therefore independent of lifting cylinders of the scraper blade and can swivel the scraper blade about a first swivelling axis when the scraper blade is disengaged from the lateral retaining devices. The arrangement of the operating device enables a large swivelling angle, since the scraper blade can be swivelled about 90° and more. A small swivelling radius is achieved at the same time because the lifting cylinders, and thus also the scraper blade itself, are not required to provide any additional lifting path for an additional swivelling movement even after completion of the actual lifting movement. A low design height of the swivelling device is realized in that the operating device is preferably arranged horizontally. In addition, swivelling of the scraper blade is effected fully automatically without requiring any manual operation.
The operating device may be arranged essentially orthogonally to the scraper blade. As a general rule, the swivelling device is to not increase the design height of the scraper device.
It is preferably provided that the retaining devices and the scraper blade are provided with locking means arranged parallel to the axis of the milling drum, where, on the blade side, the said locking means show at least one first locking means each at the two vertical lateral edges of the scraper blade which, on the machine side, interact with second locking means adapted to the first locking means when the scraper blade is in operating position or is not fully raised.
The operating device at the upper part of the scraper blade engages with an articulation of the scraper blade below the swivelling axis. As the operating device engages with the upper part of the scraper blade below the swivelling axis, the swivelling device may be of especially compact design. For swivelling, the operating device presses against the scraper blade, so that the same can be swivelled about the swivelling axis.
Relative to the articulation of the scraper blade, the swivelling axis is arranged vertically higher and offset horizontally towards the rear in relation to the scraper blade, i.e. offset towards the rear in the direction pointing away from the milling drum.
The machine-side articulation of the operating device is arranged at the permanently installed part of the construction machine also below a horizontal plane through the swivelling axis.
The articulation of the scraper blade is mounted in the plane of the upper part of the scraper blade or at a small distance from this plane.
The aforementioned features enable favourable leverage ratios and a small swivelling radius due to the fact that the two parts of the scraper blade are entirely moved together, and that a separate swivelling device is provided. In addition, a large swivelling angle of more than 90° is achieved simultaneously with a compact design.
The swivelling axis is supported at a permanently installed part of the construction machine, in particular at the machine frame or a drum casing surrounding the milling drum and attached at the machine frame.
In one embodiment, it is provided that the lower part of the scraper blade is engaged with lateral retaining devices when in operating position, and that a swivelling device can swivel the scraper blade about the swivelling axis when the lower part of the scraper blade is disengaged from the lateral retaining devices.
In addition, it may be provided that the retaining devices on the machine side are provided, on both sides of the scraper blade, with at least one each projection, which projects horizontally in the direction of the scraper blade and is engaged with a vertically running strip at the corresponding lateral edge of the lower part of the scraper blade when the scraper blade is in operating position or is not fully raised.
The projection preferably consists of a rotatable sliding block which is mounted to rotate about an axis running parallel to the axis of the milling drum. The sliding block has a preferably cuboid shape with quadratic cross-section.
In one embodiment, it is provided that the lower part of the scraper supports itself at the sliding blocks towards the rear when seen in the direction of travel.
The lower part is preferably raisable in relation to the upper part by means of a lifting device, until the lower part is disengaged from the lateral retaining devices. For swivelling of the scraper blade, the lower part of the scraper blade is raised until it has moved beyond the sliding blocks provided on both sides. When the scraper blade is moved back into the operating position, these steps are correspondingly carried out in the reverse sequence. In the process, the lower part of the scraper blade threads in again behind the two-sided sliding blocks. For this purpose, the guides of the scraper blade are provided with chamfers or roundings respectively, with the sliding blocks themselves being supported in a rotating fashion. This support also brings about an as large contact surface as possible and thus low surface pressures, which lead to low wear and tear.
Vertically running strips interacting with the sliding blocks are arranged at the lateral edges of the lower part of the scraper blade. These strips are bevelled at their bottom edge towards the scraper blade.
According to an alternative, it may be provided that the projections towards the outside are retractable automatically in order to release the lower part of the scraper blade when the lower part of the scraper blade is raised to a sufficient extent. In this alternative, it may also be provided that the upper part of the scraper, and not the lower part, supports itself at the sliding blocks towards the rear when seen in the direction of travel.
In an additional embodiment, it is provided that the upper part of the scraper blade is engaged with lateral retaining devices when in operating position, and that a swivelling device can swivel the scraper blade about the swivelling axis when the upper part of the scraper blade is disengaged from the lateral retaining devices.
It may be provided that the locking means are unlockable in order to release the upper part of the scraper blade when the lower part of the scraper blade is raised to a sufficient extent or is fully raised.
The lower part is preferably raisable in relation to the upper part by means of a lifting device, until the upper part is disengaged from the lateral retaining devices.
In this embodiment, it may be provided that the lower part of the scraper blade is provided with an unlocking device which, when raising the lower part of the scraper blade, unlocks the locking means after a pre-determined lifting path so that the scraper blade is then capable of being swivelled because of the unlocking process.
In an additional embodiment, it may be provided that the retaining devices on both sides of the scraper blade are provided, as a first locking means, with at least one each projection on the blade side which projects parallel to the axis of the milling drum in the direction of the lateral walls running orthogonally to the scraper blade, with the said projection engaging with a recess, as a second locking means, in the lateral walls when the scraper blade is in operating position or is not fully raised.
Additional advantageous embodiments can be gathered from the additional dependent claims.
The invention also relates to a construction machine, in particular an automotive road milling machine, with the scraper device according to the invention.
In the following, embodiments of the invention are explained in more detail with reference to the drawings.